E cigarettes contain hazardous substances, addictive and harmful It's Not Just Cigarettes: Vape Residue Sticks on Surfaces Too Thirdhand Smoke Resource Center Johns Hopkins researchers find thousands of unknown chemicals in electronic cigarettes Hub Do you really know what's in your vape? There's no safe vape. Besides nicotine, vapes contain many other harmful substances. Formaldehyde, arsenic and lead have all been found inside common vapes.